Treatment of locally advanced and metastatic basosquamous carcinoma, navigating among sonic hedgehog pathway inhibitors, immune checkpoint inhibitors, chemotherapy, and radiotherapy: A case series and literature review

Successful Treatment of Cutaneous Squamous Cell Cancer with Cemiplimab-A Report of Two Cases Demonstrating the Management of Pseudoprogression and Adverse Events

Background: Cutaneous squamous cell carcinoma is a common malignancy, which frequently develops in the areas exposed to the sun. Patients with locally advanced disease in the head and neck region are frequently disqualified from surgical resection and require systemic treatment. Methods: In this report, we present the clinicopathological features and treatment of two patients who received cemiplimab, a monoclonal antibody targeting programmed cell death receptor 1 (PD-1). Results: An 80-year-old female and 82-year-old male patient were admitted to the hospital for the treatment of large tumors diagnosed as squamous cell carcinomas. In both patients, surgical treatment was not recommended due to the large dimensions of the tumors. These patients qualified for systemic treatment with cemiplimab. In the first patient, immunotherapy was interrupted due to adverse events. Nevertheless, a continuous regression of the tumor was observed despite treatment cessation. The second patient experienced a pseudoprogression, which is an increase in the tumor size caused by infiltration of immune cells. The treatment significantly reduced tumor size in both patients, which highly improved their quality of life. Conclusions: Cemiplimab offers clinical benefits in patients with cutaneous squamous cell carcinoma who are ineligible for surgical treatment. Systemic treatment can significantly improve the quality of life and reduce tumor diameters.

Basosquamous Carcinoma Arising from the Vulva: A Case Report

Introduction

Basosquamous carcinoma (BSC) of the vulva is an uncommon tumor that primarily consists of basal cell carcinoma with squamous differentiation. Also known as metatypical basal cell carcinoma, BSC is typically classified as a skin cancer and represents only 2% of non-melanoma skin malignancies. This type of carcinoma has a poorer prognosis than basal cell carcinoma due to its increased local aggressiveness and metastatic potential.

Case Presentation

We present the case of a 59-year-old woman with a 3-year history of a slow-growing and painful vulvar lesion. Clinical examination revealed a 35-mm nodular, ulcerating, and non-pigmented lesion located on the labia majora. A biopsy confirmed the diagnosis of BSC, and staging assessments indicated no evidence of metastasis. The patient underwent partial radical vulvectomy and sentinel lymph node biopsy, with histological analysis revealing distinct features characteristic of BSC, including basaloid cell islands and areas of significant squamous differentiation. The excision margins were tumor-free, and all six lymph nodes examined were negative for metastases. Regular surveillance for 6 months was conducted without signs of recurrence.

Conclusion

After reviewing the literature, this case represents the sixth documented instance of vulvar BSC. Compared to basal cell carcinoma, BSC has a poorer prognosis, with a higher potential for recurrences and metastases. While basal cell carcinoma is much more prevalent among vulvar and skin malignancies, recognizing the squamous differentiation component is crucial for ensuring wider margins during surgical excision.

Basosquamous Carcinoma: Comprehensive Clinical and Histopathological Aspects, Novel Imaging Tools, and Therapeutic Approaches

Basosquamous carcinoma (BSC), an uncommon and aggressive nonmelanoma skin cancer exhibiting characteristics ranging from basal cell carcinoma (BCC) to squamous cell carcinoma (SCC), is a subject of controversy in terms of its classification, pathogenesis, histologic morphology, biologic behavior, prognosis, and management. This narrative review is based on an electronic search of English-language articles in PubMed that included the terms "basosquamous carcinoma" and/or "metatypical carcinoma of the skin" in their titles. The review aims to succinctly present and assess current data on the epidemiology, clinical presentation, dermoscopic, LC-OCT, and histopathologic characteristics, as well as the genetics and management of BSC, providing insight into this intriguing entity. As a conclusion, dermoscopy, deep incisional biopsies, and immunohistologic techniques should be applied in clinically suspicious lesions to achieve an early diagnosis and better prognosis of this tumor. Surgical treatments, including wide excision and Mohs' micrographic surgery, remain the treatment of choice. Finally, Hedgehog pathway inhibitors and checkpoint inhibitors, must be thoroughly investigated with large controlled trials, since they may offer an alternative solution to irresectable or difficult-to-treat locally advanced cases of basosquamous carcinoma.